Good animal welfare is defined, for the purposes of this article, as when an animal has both its physical needs (adequate housing, food, and water, and good health) and mental needs (able to perform normal behaviours, not frustrated, fearful, or distressed) met.
There are many perspectives on animal welfare. Some may think that an animal that is producing well has good animal welfare while others think that animals with a high level or production must have poor welfare. In reality, the link between production and welfare is more complex.
This graph, adapted from one created by Richard M. Bennett from the University of Reading in the UK, represents a simple theory on the relationship between welfare and productivity.